Error saving message

Hello, I’m using Windows 10 with Audacity 2.1.2
When I go to Save Project As I get this message:
“Save Project is for an Audacity project, not an audio file. For an audio file that will open in other apps, use Export.”
I am able to export but I can’t save it as an Audacity project to come back and work on later. Any ideas?

In Audacity 2.2.0 (only), the export commands are in "File menu > Save Other > ".
For more info, see: http://manual.audacityteam.org/man/file_menu_save_other.html